Rear Shim Question

[werd]

This is an exhausted topic and I have searched. However, I am running a 4" lift with 2-1/2" longer rear shackles. I have balanced my drive shaft and replaced both u-joints (they needed to be replaced) and I still have vibration in the rear end in 4th gear. My angles on the rear carrier are off, by angle gauge and sight. However, I know one of two options will resolve this problem.

I can revert to shorter shackles in the back. However, I like how my truck is leveled.

I could put shims on backwards they will rotate the rear carrier forwards (or down). This seems like the "easiest" solution, but this doesn't seem right since the fat part of the shim generally goes forward.

Thoughts and experiences?

Thanks!

 

[Degnol]

If you reverse the shims and point the pinion up, you'll need a double cardan driveshaft. I had the same vibration after lifting my truck 4" and used Roger's shims to point the pinion back down(useing a 2-U joint shaft) and have had no issues since. The rear output and the pinion need to be within 1*-3* of each other.

GL

Ed

 

[werd]

I have a 2 u-joint shaft and I need to rotate the pinion back down since the longer rear shackles are making the pinion angle face upwards.

Shimming it backwards (fat part of the shim towards the rear of the vehicle) would fix the problem. I am wondering if this is acceptable, since shims usually face toward the front of the vehicle.

Do Roger's shims do the same?

 

[Degnol]

Shims are shims.....Roger's are steel and made to whatever degree you need. Face the fatty-end to front or back......according to your need.

http://www.4crawler.com/4x4/ForSale/Shims.shtml#Questions



Also read this.....if you haven't already...


http://www.4xshaft.com/driveline101.html

Ed

 

[werd]

Thanks! That answers my question. I have pro-comp shims (I think they are aluminum though).

You are talking about STLCA Roger? If so, I will see him this week.

 

[rookie54]

With that much lift(about 6 inches) which is same as on mine I went with a CV joint drive shaft in the rear. if you want to know more just ask but that will for sure give you best all arount set-up.